Wide-range tunable dual-wavelength semiconductor laser using asymmetric dual quantum wells

Using asymmetric dual quantum wells for the laser material, the semiconductor laser is able to operate at dual wavelengths with an extremely wide tuning range. The spectral spacing could be tuned to as large as 55.7 mn (25 THz). With the spectral spacing fixed, the two wavelengths could also be simultaneously tuned for a range as wide as 34.7 nm. In addition, with one wavelength fixed, the other one could be separately tuned. The experiments indicate that the two wavelengths can be almost randomly selected within a large spectral range over 30 nm.